WAC 173-160-451   What are the minimum standards for direct push resource protection wells?  (1) Resource protection wells that are installed using direct push technology shall comply with the applicable standards in these rules for reporting, casing, screening, development, surface protection, cleaning, tagging, and completion.

     (2) Resource protection wells that are installed using direct push technology shall also comply with the following standards:

     (a) Prepacked or sand packed screens shall be used. The sand pack or filter pack shall not extend more than three feet above the top or one foot below the bottom of the well screen; and

     (b) The outside diameter of the bore hole shall be a minimum of one inch greater than the outside diameter of the well casing; and

     (c) Granular bentonite shall not be used in the sealed interval below the static water level. Prepacked or slurry sealant is required below static level. Any sealing method used must result in a continuous and effective seal meeting the minimum sealing standards of this chapter; and

     (d) Direct push wells shall not be constructed through more than one water bearing formation and the seal shall be from the top of the sand pack to land surface. Direct push wells shall not be greater than thirty feet in depth unless a variance is obtained. A request for a variance must be accompanied by a site-specific plan; and

     (e) If the total probe depth exceeds the depth of the bottom of the screen it must be properly decommissioned to the bottom of the screen.



[Statutory Authority: Chapter 18.104 RCW. 06-23-121 (Order 06-08), § 173-160-451, filed 11/21/06, effective 12/22/06.]